jake tapper joins us and what are law enforcement officials telling you? >> a government official says in the preliminary interviews with sfwl dzhokhar tsavraev, he is providing details, not so much talking, but by nodding and writing things down. he says there were no foreign terrorist groups involved with the attacks. they were radicalized on line. by watching videos online and getting instructions and information online. and in addition according to dzhokhar, the older brother, tamerlan, the driving force behind the attacks this is what dzhokhar is saying to investigators. investigators know they have to check everything out. not taking his word as gospel. they want to make sure that what he's saying is true, but this is what he is saying, according to government officials that we have spoken with, the brothers have seen to have been self-starter, self-radicalized individuals. seem to have been radicalized in the united states, and the motivating thought seems to be jihadist thought, the idea there is political and religious motivation, that islam is un